Human Factors in the Vineyard

Question 1

Three defining characteristics of sustainable agriculture?

Answer 1

(1) Use of man-made chemicals is not prohibited, but it is restricted
(2) Growers develop an in-depth understanding of pest life-cycles and weather forecasts, to predict and prevent a pest or disease outbreak by timing the sprays to achieve the greatest impact
(3) Biodiversity important: provides habitats for predators of pests, captures CO2 and provides nutrients for vines

Question 2

Difference between organic and sustainable agriculture?

Answer 2

Only a very limited number of the more traditional treatments against pests and diseases is allowed and only in very small quantities

Question 3

What is a universal requirement for all organic certifications?

Answer 3

The vineyard must undergo a period of conversion working to organic standards before it can be certified.

Question 4

Three defining characteristics of biodynamic agriculture?

Answer 4

(1) The vineyard soil is seen as part of a connected system with the planet Earth, the air and other planets.
(2) Practitioners adapt their grape growing practices to coincide with the cycles of the planets, moon and stars. (3) Homeopathic remedies called ‘preparations’ are used to fertilise the soil, treat diseases and ward off pests.

Question 5

What are three factors a grape grower must consider when deciding harvest timing?

Answer 5

(1) The fruit’s balance between sugar, acid, flavour and tannin
(2) Weather (hail, rain etc)
(3) Coordinating arrival of fruit at the winery to make sure it has capacity to process the fruit

Question 6

Fourdisadvantages of machine harvesting?

Answer 6

(1) Not selective (may collect unripe or unhealthy grapes or MOG)
(2) Cannot collect whole bunches, since machine harvesting involves shaking the vine and collecting the berries as they fall off
(3) Not suitable for steep slopes
(4) Not suitable for grapes that are easily damaged (e.g. thin-skinned)

Question 7

Two advantages of machine harvesting?

Answer 7

(1) Speed (important for bad weather or grapes that easily overripen)
(2) Can work at night, allowing grapes to be harvested when it is cool: (i) no need to lower grape temperature before fermentation (impt for warm climates) and (ii) slows down oxidation process

Question 8

When does the first yield come in after new vines are planted?

Answer 8

Third year after planting

Question 9

Five reasons you might hand-harvest?

Answer 9

(1) Grape selection is needed (e.g. botrytis or unevenly ripening grape varieties)
(2) Grapes are fragile (e.g. thin skins)
(3) Steep vineyard slopes (Duoro; Mosel; Rhone)
(4) Whole bunches needed (Champagne; semi-carbonic)
(5) AC laws require it

Question 10

How long must land be left fallow before re-planting?

Answer 10

Three years so the land can recover. Alternative is to do field-grafting, where new varieties are grafted onto existing rootstock, allowing grape growers to change the variety produced without having to uproot existing vines and incurring the associated downtime.

Question 11

Define “vine training”

Answer 11

Moulding the shape of the vine’s permanet wood

Question 12

What is the defining characteristic of cordon-trained vines? How are they pruned?

Answer 12

Trunk with one or more permanent horizontal arms or “cordons”

Usually spur-pruned

Question 13

What is the defining characteristic of head-trained vines and how are they pruned?

Answer 13

Relatively little permanent wood

Only a few short arms at the top of the trunk (“head”)

Can be spur or replacement cane pruned

Question 14

Define pruning. What is the objective?

Answer 14

Removal of unwanted leaves, canes and permanent wood, to shape the vine and limit its size.

The objective of pruning is to determine number and location of the buds that will form shoots in the coming growing season, ensuring that the buds are not too close together

Question 14

What are two key considerations with respect to cordon training?

Answer 14

1. Takes longer to establish due to the greater amount of permanent wood
2. Makes mechanization easier: sturdy permanent cordon with shoots positioned along its length

Question 15

Define winter pruning

Answer 15

Removal of unwanted permanent wood, to shape the vine and limit its size

Question 16

What is spur-pruning (3 points)?

Answer 16

Cutting down: (i) short sections of one-year old wood (ii) to only 2-3 buds (iii) that are distributed along the length of the vine (for cordon) or at the top of the trunk (for head training)

Question 17

What is replacement cane pruning (3 points)?

Answer 17

(i) Cutting down the permanent wood, typically retaining only 1-2 canes (ii) which are long sections of one-year-old wood with anything between 8-20 buds and (iii) tying each cane horizontally to the trellis for support

Question 18

What is a bush vine? What three vineyard management techniques would you expect to see with bush vines?

Answer 18

(1) Untrellised
(2) Head trained
(3) Spur pruned

Question 19

What is the main disadvantage of bush vines in cooler and wetter regions? How is this risk managed in Beaujolais?

Answer 19

The shade can impede grape ripening and the lack of airflow can promote disease.
In Beaujolais, the shoots of head-trained, spur-pruned vines are tied together at the tips, which helps expose bunches to air and sunlight.

Question 20

Define a trellis. How are vines fastened to the trellis?

Answer 20

Permanent structures of stakes and wires that are used to support any replacement canes and the vine’s annual growth. The vine’s canes and shoots are tied to the trellis.

Question 21

Define VSP (3 points).

Answer 21

Vertical Shoot Positioning:
(1) Train shoots vertically
(2) Tie them into place on the trellis to form a single narrow canopy
(2) Keeping shoots apart to keep canopy open, well-aerated and shade-free

Question 22

What are three reasons growers choose to trellis their vineyards? (SAM)

Answer 22

1. Sunlight: arrangement of young shoots controls the amount of Sunlight that gets into the canopy (either open canopy to increase sun exposure, or shaded canopy to reduce sunburn)
   2.** Air circulation**: important in wet climates as damp stagnant air promotes fungal diseases
2. Mechanisation: positioning the grapes and leaves in different areas of the vines, simplifying mechanical harvesting and the spraying of insectisides or fungicides

Question 23

What does “vine density” refer to?

Answer 23

Number of vines planted in a given area (usually, per hectare—area enclosed by a square with 100-metre sides—or an acre, which is 0.4 hectares)

Question 24

What vine density is ideal for vineyards in the Meseta Central, and why? How would you train the vines?

Answer 24

This area has a hot continental climate with limited annual rainfall, so drought is the main climactic threat.

Given the limited water supply,** low planting density can be beneficial as it allows each vine’s roots to take up water from a large volume of soil without having to compete against neighbouring vine roots**

The main canopy management consideration is sunburn (disease pressure not an issue since low rainfall). Should adopt either bush vines or “flop over” adapted VSP.

Question 25

What vine density is ideal in Marlborough?

Answer 25

Marlborough has plentiful soil nutrients and sufficient rainfall, which promotes vigorous vine growth.

The priority is therefore to manage vine growth using low density planting (often using multiple cordons or canes) to produce high yields of good quality grapes.

Question 26

Why might a winemaker in Bordeaux choose to plant at high density even in stony soils with low nutrient levels? (2 pints)

Answer 26

Bordeaux has a moderate maritime climate with even and sufficient levels of rainfall throughout the year.

1. A vine will grow vigorously even in barely fertile soil with sufficient water, and if left unchecked will produce green vegetative growth in preference to fruit.
2. The priority is therefore to maintain an open canopy with **strict bud control **to manage vegetative growth and ripening.
3. This can be achieved through high-density planting which provides **sufficient competition for resources among the roots **to restrict vegetative growth

Question 27

Why is winter pruning so important?

Answer 27

To manage bud levels. It is important to avoid too few buds (each bud has too much energy and grows vigorously) or too many buds (each bud has insufficient energy and vine will struggle to ripen)

Question 28

What are two trellising options in hot sunny regions? Which would you choose if you are producing a high-volume inexpensive wine?

Answer 28

(1) Untrellised bush vines, since the shoots hang down almost to the ground, shading the grapes
(2) Adapted VSP where the tops of the shoots are allowed to flop over instead of being tied in, providing some canopy shade to protect the fruit

If harvesting at high volumes and inexpensively, might prefer a machine harvester. In that case, adapted VSP is preferable as bush vines cannot be machine harvested.